a = 10
b = 20
c = 30

# print(a < b < c)
# print(a < b and a < c)
#
# print(a < b or b > c)
#
# print(not a < b)
# print(not a > b)

# 短路求值
print(a > b and 10 / 0 == 1)
print(a < b or 10 / 0 == 1)

# 赋值
a = b = 40 # 链式赋值
print(f"{a + b}")

a,b = 20,30
print(f"{a + b}")
# 交换
a,b = b,a
print(a)
print(b)